Conventionally, there is a case in a medical site in which a medical doctor performs a diagnosis by using an x-ray computed tomography image (hereinafter, referred to as the “CT image”). For example, CT images taken in different photographing periods are displayed side by side on a display device, and the CT images are compared with each other to check how a lesion area has changed.
The following patent document discloses a background art.
Patent Document 1: Japanese Laid-Open Patent Application No. 2008-510247
There may be a variation in the position and angle of the lesion area in the CT images taken in different periods due to a difference in patient's position and a difference in the breathing timing of the patient. Accordingly, it may be difficult for a medical practitioner to accurately recognize a location of a focusing portion. Thus, it may be difficult for a medical practitioner to compare the changes in the focused lesion area.